Data recording cartridges and recorders adapted for their use are disclosed and claimed in U.S. Pat. No. 3,692,255 (von Behren). The cartridge there disclosed includes an enclosure together with an endless flexible belt in frictional contact with the tape on both reel hubs for bi-directionally driving the tape. The cartridge can operate to drive the tape with rapid accelerations and decelerations, such as are encountered in digital data recording and playback. Recorders adapted to use such data cartridges originally employed fixed, multi-track heads which were complex, expensive and difficult to maintain in proper alignment.
To eliminate the multi-track heads, U.S. Pat. No. 4,313,143 (Zarr) disclosed a head positioning mechanism by which a single track head could be transversely positioned with respect to the width of the recording tape to enable recording and playback of any of a plurality of parallel tracks.
U.S. Pat. No. 4,750,067 (Gerfast) discloses a head positioning mechanism for a multi-track data cartridge recorder, including a stepper motor, a lead screw driven by the stepper motor, and a head mounting slide engaged with the lead screw by a partial female thread. The Gerfast mechanism moves a record/playback head transversely to the path of a magnetic recording tape. While the Gerfast mechanism works satisfactorily for some applications, an on-going desire to increase the areal recording density by providing more, narrower tracks has resulted in a need for a mechanism which more accurately positions a magnetic record/read head on the center of a selected track in response to servo signals derived from servo information carried on certain tracks on a multi-track tape.
Most prior art data cartridge tape drives use stepper motors to perform track-follow or track-seek functions. The step size of such a stepper motor is typically large, and the step response is slower than, for example, a voice coil actuator as employed by the present invention. Such relatively large steps necessarily restrict track density. The present invention, through the use of a voice coil actuator, enables one to access high track density formats.